1. Field of the Invention
This invention relates to the use of a particular combination of antistatic compounds to produce synergism in the dissipation of static electricity from a polymer host for the compounds.
2. Description of Related Art
Polymer films in the course of their handling during manufacture can develop high charges of static electricity which can have harmful consequences ranging from sparking, possibly causing fires, to adhering to oppositely charged surfaces to interfere with use of the film in packaging operations. For example, film used to package food may be more advantageously handled in the packaging operation if the film is not attracted to the food. Film attraction for the food can prevent the desired wrinkle-free packaging of the food by the film.
A wide variety of antistatic compounds are available for incorporation into polymer films for reducing static electricity charges of the film, with varying efficacy depending on the polymer and the antistatic compound and the amount of compound that can be tolerated by the film before suffering loss of other desired properties. A publication of ICI Specialty Chemicals entitled "ATMER.RTM. Antistatic Agent for Thermoplastic Polymer Applications" (11/87) discloses a large number of antistatic compounds.
In the case of film of ethylene/carboxylic acid copolymer which may be partially neutralized to form ionomer, improvement in its antistatic performance is desired. Heretofore, there has not been a commercially viable antistatic additive for incorporation into this acid polymer in film form.